# Pastebin cs2Ag51F
ffmpeg -i episode4_final.mp4 -i endslate-new.mp4 -filter_complex '[0:a][0:v][1:a][1:v]concat=n=2:v=1:a=1[v][a]' -map '[v]' -map '[a]' out
ffmpeg version 2.1.4 Copyright (c) 2000-2014 the FFmpeg developers
  built on Jul 15 2014 21:05:03 with gcc 4.9.0 (GCC) 20140521 (prerelease)
  configuration: --prefix=/usr --disable-debug --disable-static --enable-avresample --enable-bzlib --enable-dxva2 --enable-fontconfig --enable-gpl --enable-libass --enable-libbluray --enable-libcaca --enable-libcelt --enable-libdc1394 --enable-libgsm --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libpulse --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libv4l2 --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxvid --enable-openal --enable-postproc --enable-runtime-cpudetect --enable-shared --enable-vaapi --enable-vda --enable-vdpau --enable-version3 --enable-x11grab
  libavutil      52. 48.101 / 52. 48.101
  libavcodec     55. 39.101 / 55. 39.101
  libavformat    55. 19.104 / 55. 19.104
  libavdevice    55.  5.100 / 55.  5.100
  libavfilter     3. 90.100 /  3. 90.100
  libavresample   1.  1.  0 /  1.  1.  0
  libswscale      2.  5.101 /  2.  5.101
  libswresample   0. 17.104 /  0. 17.104
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'episode4_final.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.19.104
  Duration: 00:18:25.26, start: 0.022154, bitrate: 5072 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 4747 kb/s, 16.59 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: mp3 (mp4a / 0x6134706D), 44100 Hz, stereo, s16p, 320 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x17cc320] Invalid SampleDelta in STTS -14848
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'endslate-new.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.19.104
  Duration: 00:01:01.15, start: 0.025057, bitrate: 806 kb/s
    Stream #1:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 490 kb/s, 30.02 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #1:1(und): Audio: mp3 (mp4a / 0x6134706D), 44100 Hz, stereo, s16p, 320 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Stream specifier ':a' in filtergraph description [0:a][0:v][1:a][1:v]concat=n=2:v=1:a=1[v][a] matches no streams.